// Maps的函数-map-keys($map)
$font-weights: (
    "regular": 400, 
    "medium": 500, 
    "bold": 700
);
@debug map-keys($font-weights); // "regular", "medium", "bold"  




$social-colors: (
    dribble: #ea4c89,
    facebook: #3b5998,
    github: #171515,
    google: #db4437,
    twitter: #55acee
);
// #{".btn-"#{name}}
@each $name in map-keys($social-colors) {
    .btn-#{$name} {
        color: colors($name);
    }
}

/* .btn-dribble{ color: colors(dribble);}
.btn-facebook{ color: colors(facebook);} */